storage/devicelibs/swap.py

# swap.py
# Python module for managing swap devices.
#
# Copyright (C) 2009  Red Hat, Inc.
#
# This copyrighted material is made available to anyone wishing to use,
# modify, copy, or redistribute it subject to the terms and conditions of
# the GNU General Public License v.2, or (at your option) any later version.
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY expressed or implied, including the implied warranties of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
# Public License for more details.  You should have received a copy of the
# GNU General Public License along with this program; if not, write to the
# Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301, USA.  Any Red Hat trademarks that are incorporated in the
# source code or documentation are not subject to the GNU General Public
# License and may only be used or replicated with the express permission of
# Red Hat, Inc.
#
# Red Hat Author(s): Dave Lehman <dlehman@redhat.com>
#

import resource

import iutil
import os

from ..errors import *
from . import dm

import gettext
_ = lambda x: gettext.ldgettext("anaconda", x)


def mkswap(device, label='', progress=None):
    # We use -f to force since mkswap tends to refuse creation on lvs with
    # a message about erasing bootbits sectors on whole disks. Bah.
    argv = ["-f"]
    if label:
        argv.extend(["-L", label])
    argv.append(device)

    rc = iutil.execWithPulseProgress("mkswap", argv,
                                     stderr = "/dev/tty5",
                                     stdout = "/dev/tty5",
                                     progress=progress)

    if rc:
        raise SwapError("mkswap failed for '%s'" % device)

def swapon(device, priority=None):
    pagesize = resource.getpagesize()
    buf = None
    sig = None

    if pagesize > 2048:
        num = pagesize
    else:
        num = 2048

    try:
        fd = os.open(device, os.O_RDONLY)
        buf = os.read(fd, num)
    except OSError:
        pass
    finally:
        try:
            os.close(fd)
        except (OSError, UnboundLocalError):
            pass

    if buf is not None and len(buf) == pagesize:
        sig = buf[pagesize - 10:]
        if sig == 'SWAP-SPACE':
            raise OldSwapError
        if sig == 'S1SUSPEND\x00' or sig == 'S2SUSPEND\x00':
            raise SuspendError

    if sig != 'SWAPSPACE2':
        raise UnknownSwapError

    argv = []
    if isinstance(priority, int) and 0 <= priority <= 32767:
        argv.extend(["-p", "%d" % priority])
    argv.append(device)
        
    rc = iutil.execWithRedirect("swapon",
                                argv,
                                stderr = "/dev/tty5",
                                stdout = "/dev/tty5")

    if rc:
        raise SwapError("swapon failed for '%s'" % device)

def swapoff(device):
    rc = iutil.execWithRedirect("swapoff", [device],
                                stderr = "/dev/tty5",
                                stdout = "/dev/tty5")

    if rc:
        raise SwapError("swapoff failed for '%s'" % device)

def swapstatus(device):
    alt_dev = None
    if device.startswith("/dev/mapper/"):
        # get the real device node for device-mapper devices since the ones
        # with meaningful names are just symlinks
        try:
            alt_dev = "/dev/%s" % dm.dm_node_from_name(device.split("/")[-1])
        except DMError:
            alt_dev = None

    lines = open("/proc/swaps").readlines()
    status = False
    for line in lines:
        if not line.strip():
            continue

        swap_dev = line.split()[0]
        if swap_dev in [device, alt_dev]:
            status = True
            break

    return status

1	# swap.py
2	# Python module for managing swap devices.
3	#
4	# Copyright (C) 2009 Red Hat, Inc.
5	#
6	# This copyrighted material is made available to anyone wishing to use,
7	# modify, copy, or redistribute it subject to the terms and conditions of
8	# the GNU General Public License v.2, or (at your option) any later version.
9	# This program is distributed in the hope that it will be useful, but WITHOUT
10	# ANY WARRANTY expressed or implied, including the implied warranties of
11	# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
12	# Public License for more details. You should have received a copy of the
13	# GNU General Public License along with this program; if not, write to the
14	# Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
15	# 02110-1301, USA. Any Red Hat trademarks that are incorporated in the
16	# source code or documentation are not subject to the GNU General Public
17	# License and may only be used or replicated with the express permission of
18	# Red Hat, Inc.
19	#
20	# Red Hat Author(s): Dave Lehman <dlehman@redhat.com>
21	#
22
23	import resource
24
25	import iutil
26	import os
27
28	from ..errors import *
29	from . import dm
30
31	import gettext
32	_ = lambda x: gettext.ldgettext("anaconda", x)
33
34
35	def mkswap(device, label='', progress=None):
36	# We use -f to force since mkswap tends to refuse creation on lvs with
37	# a message about erasing bootbits sectors on whole disks. Bah.
38	argv = ["-f"]
39	if label:
40	argv.extend(["-L", label])
41	argv.append(device)
42
43	rc = iutil.execWithPulseProgress("mkswap", argv,
44	stderr = "/dev/tty5",
45	stdout = "/dev/tty5",
46	progress=progress)
47
48	if rc:
49	raise SwapError("mkswap failed for '%s'" % device)
50
51	def swapon(device, priority=None):
52	pagesize = resource.getpagesize()
53	buf = None
54	sig = None
55
56	if pagesize > 2048:
57	num = pagesize
58	else:
59	num = 2048
60
61	try:
62	fd = os.open(device, os.O_RDONLY)
63	buf = os.read(fd, num)
64	except OSError:
65	pass
66	finally:
67	try:
68	os.close(fd)
69	except (OSError, UnboundLocalError):
70	pass
71
72	if buf is not None and len(buf) == pagesize:
73	sig = buf[pagesize - 10:]
74	if sig == 'SWAP-SPACE':
75	raise OldSwapError
76	if sig == 'S1SUSPEND\x00' or sig == 'S2SUSPEND\x00':
77	raise SuspendError
78
79	if sig != 'SWAPSPACE2':
80	raise UnknownSwapError
81
82	argv = []
83	if isinstance(priority, int) and 0 <= priority <= 32767:
84	argv.extend(["-p", "%d" % priority])
85	argv.append(device)
86
87	rc = iutil.execWithRedirect("swapon",
88	argv,
89	stderr = "/dev/tty5",
90	stdout = "/dev/tty5")
91
92	if rc:
93	raise SwapError("swapon failed for '%s'" % device)
94
95	def swapoff(device):
96	rc = iutil.execWithRedirect("swapoff", [device],
97	stderr = "/dev/tty5",
98	stdout = "/dev/tty5")
99
100	if rc:
101	raise SwapError("swapoff failed for '%s'" % device)
102
103	def swapstatus(device):
104	alt_dev = None
105	if device.startswith("/dev/mapper/"):
106	# get the real device node for device-mapper devices since the ones
107	# with meaningful names are just symlinks
108	try:
109	alt_dev = "/dev/%s" % dm.dm_node_from_name(device.split("/")[-1])
110	except DMError:
111	alt_dev = None
112
113	lines = open("/proc/swaps").readlines()
114	status = False
115	for line in lines:
116	if not line.strip():
117	continue
118
119	swap_dev = line.split()[0]
120	if swap_dev in [device, alt_dev]:
121	status = True
122	break
123
124	return status
125